Sometimes, a costume can be a portal to a character. In this photo from the upcoming movie “Harriet,” Cynthia Erivo portrays American hero Harriet Tubman, who escaped slavery in the mid-19th century and later helped hundreds of others find their way safely north on the Underground Railroad. She’s wearing a worn, fraying Civil War general’s uniform — part of her evolution, said Erivo in an interview, saying that the goal was for the costumes to let the audience “see her growth through what she was wearing.” Here, she’s become a general, leading her troops; a woman turned superhuman. The film’s costumes were created by Paul Tazewell, whose designs have ranged from Broadway (“Hamilton”) to ballet (PNB’s production of “Swan Lake”), opera (Seattle Opera’s recent “Porgy and Bess”) and film (the upcoming remake of “West Side Story”). Taking inspiration from photographs of the period, Tazewell and his crew worked hard to age the “Harriet” costumes to reflect the hard lives of those who wore them; scrubbing the garments with sandpaper and dying or painting them to make them look faded. “Harriet” opens in Seattle-area theaters Nov. 1.